//char * strncpy ( char * destination, const char * source, size_t num );
//char * strncat ( char * destination, const char * source, size_t num );
//int strncmp ( const char * str1, const char * str2, size_t num );


//#include<stdio.h>
//#include<string.h>
//int main()
//{
//    //strncpy()函数
//    char arr1[50]={0};
//    char arr2[]="hello word!";
//    printf("%s\n",strncpy(arr1,arr2,5));

//    //strncat()函数
//    char arr3[]="Hello ";
//    char arr4[]="code! worde!";
//    printf("%s\n",strncat(arr3,arr4,5));

//    //strncmp()函数
//    char arr5[]="abcdefg";
//    char arr6[]="abcghij";
//    printf("%d\n",strncmp(arr5,arr6,3));
//    printf("%d\n",strncmp(arr5,arr6,4));


//    return 0;
//}


